Muscle contraction requires a shortening of the sarcomere, the basic contractile unit of muscle, caused by the sliding of interdigitating thick and thin filaments. Thick filaments are bipolar structures containing myosin II, MyBP-C and titin, as well as several other proteins near the bare zon...
On the other hand, sarcomeres can exhibit steady spontaneous oscillation of force and length at a fixed, intermediate level of Ca2+1,2,3,4,5. This phenomenon is called SPOC (Spontaneous Oscillatory Contraction)6,7. Although the molecular mechanism of SPOC has been extensively studied, it has...